How exactly do the FJ80 Lockers work?

[Horribilis]

I am currently in a Jeep XJ...or at least I was until it was stolen 2 weeks ago. So now I am looking into getting my replacement off-roading/hunting rig.

On the XJ it was easy - throw in a lunchbox locker front and rear and it was good to go.

I keep reading about a "center" locker on the FJ80's - WTH is a center locker? Does the locker switch on the FJ80 work like on the Jeep Wrangler Rubicons (flip the switch and it locks front and rear with factory lockers)?

What is the stock gearing in 80's? I've seen some 4.10 references and some 4.88 - but not sure which is correct or if both are.

My XJ had a 4.5" lift on 33's with great articulation. I'm looking at the FJ80's for a few reasons:

1) more room in the way back for the mutts
2) possibility of factory lockers (provided that the answers here are good)
3) body on frame versus unibody
4) stronger axles to start with

What else am I missing?

Thanks in advance for thoughtful input.

 

[Frankencruiser]

Check out the FAQ section and report back. All your questions will be answered.

 

[captfzzy]

lc has better wheelbase diff lock locks output shafts to turn @ same rate factory lockers if your lookn to buy is imho the way to go mine has 4.10 raito as most are. mine also has 33s and no lift required at all, room for bigger tires it still has. land cruiser is a far superior out of the box wheeler not many mods necc. to wheel hard ditch the running boards dude and find one with shot paint. who knows scumbags might not steal that one lol

 

[CMY4XGO]

X2 - The 80 series is a stout platform that out shines most other vehicles like it, if not all of them.

Im factory locked, no issues to report.

Welcome to MUD

 

[WarDamnEagle]

All of the 80 series in the US (to my knowledge anyway) have an automatic transmission. The center diff lock effectively locks the transfer case so that the drive shafts turn at the same speed front and rear regardless of what else is happening. The diff lock is activated by shifting into low range or by pushing a button if you have the button installed (they are all wired for the button) in which case you can lock the center diff in high range.

The front and rear lockers are electric and are activated by turning a switch on the dash (left of steering wheel). They basically lock the axles as if they were welded. Your choices are rear locked only or front and rear locked. You can't lock just the front (without modificiatons anyway).

Hope that helps.

 

[Horribilis]

Check out the FAQ section and report back. All your questions will be answered.

I check the FAQ first - which lead to my follow-up/clarification questions. It talked about factory lockers but not exactly how they work. There was also mention of 4.10 and 4.88 in the FAQ, but no mention of which is most prevalent.

So at this point I am still a little unclear about the references of a center locker as opposed to a front and rear.

So - on the FJ80 does center locker mean that it locks the front and rear driveshafts? Like on the XJ putting the T-case into 4-hi or 4-lo? What about the axles? Are they truly locked? Or does the factory locker just get both front and rear driveshafts locked in?

 

[Horribilis]

WarDamnEagle - thanks for the answer - that is exactly what I was looking for. So when looking at Fj80's I need to make sure that they have 2 lock knobs/switches....one for the T-case and one for the axles - correct?

 

[Chris Wilcox]

I think most if not all 80's have a center diff lock. It is like putting a regular 4x4 in low range so both front and rear driveshafts turn at the same speed and angular relationship.

The optional and somewhat rare front and rear factory lockers are the equivalent to and ARB or jeep rubicon diff locks, only the 80's are electric. Just imagine you take your center diff, rear diff and front diff and weld them all solid. That is what you have with 3 lockers. All 4 tires turn at the same rate and relationship, regardless of if it is touching the ground, on ice etc. Very hard to turn on some surfaces and therefor not recommended to be used on asphalt by me at least.

If you need more info than this to understand it then you need to brush up on your understanding of 4x4's. If you want an in depth understanding on the exact design and function of the 80 locker there are threads that show how to rebuild an electric actuator and other to re-gear a locked diff (search ZUK gear installs) You will get your info.

Chris

EDIT I'm a slow typer and you responded above after I started this response... You will want to look for the dash rotary knob and of course dive underneath and look for the electric actuators hanging off the diffs. Boston Mangler has a good writeup but it may be a dead link here http://www.yankeetoys.org/mangler/elockerinstall.htm

 

[e9999]

WarDamnEagle - thanks for the answer - that is exactly what I was looking for. So when looking at Fj80's I need to make sure that they have 2 lock knobs/switches....one for the T-case and one for the axles - correct?

no -usually- and yes

the OEM electric axle diff lockers are actuated by an electric rotary switch on the dash to the left of the steering wheel, that gives you the choice of rear only or rear and front both. This is a highly sought option and reported to be installed on only about 10% of the trucks.

On at least the later 80s, the center diff locker is normally actuated automatically when put in low range when stock OTOH, without a manual switch operated by the driver so there won't be a switch for that inside the cab. The (later?) 80s all have that feature IIRC. No switch that is, unless the truck has been modded by a previous owner, with a manual electric switch typically inserted in the center dash section where there are suitable blanks and a harness connector ready to go. This is a mod that is not uncommon with MUD 80 owners and has been amply described here, but that you are highly unlikely to find on a soccer mom's truck. But easy/cheap to retrofit anyway. (The reference to the "later" 80s above refers to the fact that the first couple years or so of 80s did have some funky leftovers from the 60 series, such as SF rear axles, drum brakes, smaller engine etc, and may have been set differently locker / switch -or not- wise, I don't remember exactly. For instance, earlier 80 trucks may well all have had the center switch, I don't recall, but didn't have axle lockers. Importantly, the owners of the actual FJ80s -in contrast to the later FZJ80s- are a different breed on MUD and in particular you need to be careful when discussing engine power with them ... And so, since they are a bit touchy about their trucks, they will surely point out shortly any advantage they may have over the later trucks, and correct me if I'm wrong about their switches and lockers... )

You might also be interested in knowing that the FZJ80 is a full-time 4wd, which of course requires a center diff, but has also a viscous coupler in the TC that allows for a certain measure of "semi-locking" of the center diff, for yet better traction when not fully locked in the center.

 

[4x4CPOSEADOG]

Take a look at this link
Welcome to Land Cruiser Owners On Line




<<<<<<<<<< Front and Rear Diff Lock Switch in motion.

I am currently in a Jeep XJ...or at least I was until it was stolen 2 weeks ago. So now I am looking into getting my replacement off-roading/hunting rig.

On the XJ it was easy - throw in a lunchbox locker front and rear and it was good to go.

I keep reading about a "center" locker on the FJ80's - WTH is a center locker? Does the locker switch on the FJ80 work like on the Jeep Wrangler Rubicons (flip the switch and it locks front and rear with factory lockers)?

What is the stock gearing in 80's? I've seen some 4.10 references and some 4.88 - but not sure which is correct or if both are.

My XJ had a 4.5" lift on 33's with great articulation. I'm looking at the FJ80's for a few reasons:

1) more room in the way back for the mutts
2) possibility of factory lockers (provided that the answers here are good)
3) body on frame versus unibody
4) stronger axles to start with

What else am I missing?

Thanks in advance for thoughtful input.

 

[firetruck41]

As 4x4CPOSEADOG mentioned above, read this for how the diff locks function on the 80 series:
Welcome to Land Cruiser Owners On Line

 

[Horribilis]

The posts by War and Chris cleared it up the lockers situation for me. On my XJ I put a lunchbox locker both front and rear, so I am well versed on what locking does...but just now stepping into the FJ80 world and hearing that some actually have selectable full lock had me wondering how it was done, and I have seen at least one early (1992) FJ80 that had an actual T-case/Center lock switch in the middle of the dash.

So now that this is cleared up, I think the FAQ covers quit a bit, including the Slee link on what to look for when shopping.

Any quick advice otherwise?

 

[jfz80]

Any quick advice otherwise?

Be patient!
Dont rush into your decision as it sounds there is lots more for you to learn to make the best choice for yourself.

The FAQ section works best when your read and digest it rather than a quick scan. There is a huge amount of information there, and all that you asked is covered there.

The links provided to you by some generous club members is actually in FAQ-chapter 2. Youll find its a great group here and willing to lend a hand but we can also appreciate those that are willing to help themselves as well. That is not meant to be a harsh comment directed towards you but rather in general lately there have been numerous newbies on board that ask for the answer and say they have searched FAQ but the nature of their questions indicates otherwise. Again its a great wealth of knowledge accumulated by mud and compiled and organized through the hard work or our moderators (esp romer) so it would be a shame for it to not be used to the fullest.

as for the CDL button you witnessed it come std on the FJ80's but as metioned previously the wiring is present on all 80 models and its as simple as a plug and play switch to add on the FZJ80s and 450's. As well the center is locked when put into low range. Sounds like you understand this eliminates the effect of the viscous coupler and generates an equal 50/50 split of power from the t-case fore and aft.

The Full time 4WD is the biggest difference coming from your xj. This keeps you from just throwing a lunchbox locker up front as you cant separate it from the whole system without adding front hubs and doing away with the AWD aspects which really make the 80 shine in my opinion. Do realize though that while the factory lockers are an incredible option it shouldnt be a deal breaker. A 300 dollar aussie locker in the rear and youll outwheel your XJ and thats before you add the ARB up front

oh and 4.10s are factory gears if your still looking for that one

 

[Tools R Us]

...
Any quick advice otherwise?

If there is a club, group in your area, hook up with them. Find out what is preferred, works in the local terrain, etc.